We demonstrate the possibility of using a femtosecond laser to measure with high accuracy the frequency of a far-infrared (FIR) monochromatic source, such as an optically pumped molecular laser, by generating in a suitable mixer a signal in the radio-frequency region at the frequency difference between n steps of a femtosecond comb and the FIR source. All the couples of modes lying a distance of n steps from one another contribute coherently to the heterodyne signal. The technique has been tested up to 670 GHz. (C) 2005 Optical Society of America.
|Autori:||Beverini N; Carelli G; De Michele A; Maccioni E; Nyushkov B; Sorrentino F; Moretti A|
|Titolo:||Coherent multiwave heterodyne frequency measurement of a far-infared laser by means of a femtosecond laser comb|
|Anno del prodotto:||2005|
|Digital Object Identifier (DOI):||10.1364/OL.30.000032|
|Appare nelle tipologie:||1.1 Articolo in rivista|